Curiosity lands on Mars

Most challenging robotic mission ever attempted is a success so far.

Mars Science Laboratory arrived at its destination Sunday night at 10:31pm Pacific Time. The MSL team at NASA's Jet Propulsion Laboratory's control center in Pasadena was ecstatic; the mission control room was flooded with jubilant pandemonium. According to NASA Administrator Charlie Bolden, who was there along with Deputy Administrator Lori Garver and Presidential Science Advisor John Holdren, "Everybody in the morning should be sticking their chests out saying, 'That's MY Curiosity rover on Mars!'" The rover is checking out in perfect shape so far, and soon the science will begin.

Progress reports rolled in last night at a rate of about one per minute. Each time a milestone in the intricate system was transmitted home, the team clapped and broke out in spontaneous laughter.

The first two pictures from Curiosity as they were displayed for JPL mission control

Photo credit: NASA JPL video screen capture

Ecstasy breaks out in the JPL Mission Control Room.

Photo credit: NASA JPL video screen capture

Some events in the control room timeline as they arrived (14 minutes after they actually took place on Mars):

Touchdown time was 10:14:39pm Pacific Time, with 140.46kg of fuel remaining (out of 400kg to start) in the descent stage as it flew away. There's no doubt we'll visit that descent stage again some day.

Scientists and engineers at JPL will spend the next several hours sorting through data relayed from two other spacecraft in orbit around Mars. Mars Odyssey and Mars Reconnaissance Orbiter were catching the telemetry from Curiosity and sending it home to Earth.

At the press conference this morning, John Holdren said Curiosity is "the most challenging mission ever attempted in the history of robotic exploration." Anyone who has watched the NASA JPL video Seven Minutes of Terror (the website has been knocked offline due to large amounts of traffic) knows why. The Mars Science Laboratory spacecraft weighed almost four metric tons at launch. Even after using much of its fuel, it was far too large to land using anything NASA has ever tried before.

There are basically three ways to land a spacecraft on Mars, which has an atmosphere one percent of the density of Earth's. Reentry shields and parachutes work to slow down the spacecraft, but not nearly as well as they do on Earth.

The Viking probes used rockets to slow the spacecraft in the air and lower them gently to the Martian surface. The Mars Exploration Rovers, Spirit and Opportunity, used a similar system to suspend them 10 to 15 meters above the surface. They then popped giant airbags and fell the rest of the way.

Curiosity's landing system worked much the same way as its predecessors' down to a few tens of meters above the surface. To begin, a giant 4.5m aerodynamic heat shield, the largest ever flown in space, slowed the spacecraft down to about 470 meters per second. That was slow enough for Curiosity's 16m incredibly strong, supersonic parachute to pop out and slow Curiosity down further to about 100 meters per second—better, but still pretty fast.

At that point, about 1.8 kilometers above the ground, the parachute was cut loose, and the descent stage's rockets began firing. During this time, Curiosity began to unfold. The rockets lowered the craft down to only 7.6 meters above the surface, just a few stories. So far, very similar to previous probes, except much larger.

But at 900kg, Curiosity was much too large to drop to the surface using giant airbags. Instead, it was lowered to the surface using cables from the descent stage. Once landed, explosive bolts detached the cables and the "skycrane" sped away to land well out of the way.

The landing site itself is in Gale Crater, named for Walter Frederick Gale, the amateur Australian astronomer who spotted what he thought were canals on the Martian surface. Gale Crater contains a mountain of layered rocks that looks like a great geological target, a smooth region of material washed down from the sides that makes another good target and a place to land without boulders, and some very brightly colored, very dense rocks that may have once formed a dry lakebed. These rocks are a good place to check for organic molecules and evidence of life on Mars.

Curiosity is a mobile laboratory of unprecedented scale. It has seventeen cameras and several remote sensing instruments, including a laser-driven breakdown spectrometer, an X-ray spectrometer, an X-Ray diffraction instrument, a radiation assessment detector, a pulsed neutron source and detector, and a meteorological package. It also houses the entry descent and landing instrumentation, plus hazard avoidance and navigation cameras. To land all of this instrumentation intact is an amazing victory for the seven countries that participated in the spacecraft: Finland, Spain, Canada, Russia, France, Germany, and the United States. It's especially amazing that we're back up to two operating rovers on Mars again, counting Opportunity.

Right now, Curiosity is being checked out on the surface, but it's transmitting video, and all is very, very well in Pasadena. It's doubtful that the Curiosity team (or Curiosity's many fans and followers) will sleep for the next day or two.

Promoted Comments

When I first saw the sheer complexity of this Mars landing, I thought this was so complex that it was bound to fail somehow. I'm glad to see I was wrong. That's an heck of an achievement that the NASA pulled off.

191 Reader Comments

This will never cease to amaze me. The sheer amount of planning/engineering/coding that needs to take place correctly in order to pull this off is is a monumental statement on the power of math and science. Unfortunately I was distracted last night and forgot this was taking place. Great stuff. Simply amazing.

Bit off topic: Anyone want to bet that special attention was paid to imperial/metric conversions this time?

This will never cease to amaze me. The sheer amount of planning/engineering/coding that needs to take place correctly in order to pull this off is is a monumental statement on the power of math and science. Unfortunately I was distracted last night and forgot this was taking place. Great stuff. Simply amazing.

Agreed -- this is amazing -- though I'm a little biased since my cousin is on the Curiosity team (he's an engineer and helped design the rover and it's landing apparatus).

Quote:

Bit off topic: Anyone want to bet that special attention was paid to imperial/metric conversions this time?

Well if the Americans would come to the dark side and embrace the Metric system, these things wouldn't happen

To echo my thoughts from the observatory thread, few things inspire more awe in me than when science fiction becomes science fact. Truly an awesome day, and a big CONGRATULATIONS to all of the NASA, JPL, and other engineers, technicians, rocket scientists, etc. who made this happen.

Can't wait for the data to start pouring in. I'm especially looking forward to the images of the descent that HiRISE captured. They should be released later today (western hemisphere time).

cdcIndc wrote:

Bit off topic: Anyone want to bet that special attention was paid to imperial/metric conversions this time?

I kind of hope they just ditched imperial entirely and stuck with metric. Less chances of screw-ups.

I'm still up from last night, myself. Really incredible to be watching live as the telemetry came in (14 minutes after the fact). A few highlights were hearing that the parachute was deployed, and actually causing deceleration. Next that the rockets were firing. Finally, that the sky crane maneuver was beginning and actually seemed to be working. When touchdown was confirmed, I couldn't even really believe it. When pictures started coming in just minutes later, wow. It all just seemed to happen so quickly, and so perfectly. Hearing in the press conference later that everything was done particularly well, I'm elated. It'll take a while to get really specific information, but it sounds like they were right on target the whole way with fewer problems than anticipated.

I'm just really glad Odyssey got into position and stayed high enough in the sky long enough for us to get what little data we got. It would have been agonizing waiting for confirmation otherwise.

I have to confess that I haven't been following the Curiosity as closely as I would normally do. I love this stuff and was thrilled to hear that it made it okay. It's an incredible feat of engineering and I'm looking forward to the information we get back.

I am absolutely floored. The "7 Minutes Of Terror" video is an incredible watch, and I viewed it several times over the past couple of weeks. I am truly amazed everything actually worked as planned. If I heard correctly, I believe the director said they were expecting a 40% chance of actually pulling it off. I think if I was managing a 2.5 billion dollar project I would state low odds no matter what. What a huge win all around for NASA and the various agencies and countries involved. As incredible a feat this landing was, the most exciting part will be the data collected. Go science!

I am absolutely floored. The "7 Minutes Of Terror" video is an incredible watch, and I viewed it several times over the past couple of weeks. I am truly amazed everything actually worked as planned. If I heard correctly, I believe the director said they were expecting a 40% chance of actually pulling it off. I think if I was managing a 2.5 billion dollar project I would state low odds no matter what. What a huge win all around for NASA and the various agencies and countries involved. As incredible a feat this landing was, the most exciting part will be the data collected. Go science!

The 40% number was based on the record Mars missions have had, not so much the actual likelihood of THIS mission succeeding.

And, from personal experience - testing. Lots and lots of simulation and testing. Mechanical actuators may malfunction when you're speeding through the atmosphere or experiencing 9G, and there's nothing you can do about that. But software should not.

cdclndc wrote:

Bit off topic: Anyone want to bet that special attention was paid to imperial/metric conversions this time?

I really hope they had quit using imperial units at this point. These have absolutely no place in robotics.

I participate in programs to get High School Sophmores and Juniors interested in careers in STEM. This one event will do more than I could do in a lifetime. But, I will press on. (BTW, half the time when I ask the students if they know what a Civil Engineer does, I get just the response you would expect).

Sticking to metric doesn't, in and of itself, somehow eliminate the pitfalls of unit conversion--you're just as screwed if you botch a conversion from km to m as you are if you botch one from ft to m. What helps is if you establish a consistent set of units, say m-kg-s, and avoid all unit conversions to the extent practicable. Your computer program (or robot as it were) doesn't care what your units are as it can understand a million furlongs just as well as 2.01 Gm. So if you want to use US Standard units, there's no problem, just pick a consistent set, say ft-slug-s, and you're fine. I suspect no spacecraft has ever made intra-imperial unit conversions (e.g. 12 inches = 1 foot) in flight, because it's just not necessary. Even in US engineering industries where we still use these units, we'll talk about things in decimal feet (or decimal inches, depending on the field, but never both!).

I find the people who get most worked up about units are the people who are pretty well educated, but don't actually work with them on a daily basis--it's just not that hard and really not a big deal in practice. The problem isn't units--it's poor software engineering practices.

Why do you think we only have a couple of pictures so far? They knew they'd have to embargo the bit where Curiosity says Hi to the Little Green Men. Then they're going to have to carefully sweep the area clear of alien footprints before sending back detailed pics.

But seriously, this is incredibly great work, and they landed it beautifully softly. Only real question I have right now is to get official data about the touchdown location.

When I first saw the sheer complexity of this Mars landing, I thought this was so complex that it was bound to fail somehow. I'm glad to see I was wrong. That's an heck of an achievement that the NASA pulled off.

Really incredible to be watching live as the telemetry came in (14 minutes after the fact). A few highlights were hearing that the parachute was deployed, and actually causing deceleration. Next that the rockets were firing. Finally, that the sky crane maneuver was beginning and actually seemed to be working. When touchdown was confirmed, I couldn't even really believe it. When pictures started coming in just minutes later, wow. It all just seemed to happen so quickly, and so perfectly

I wasn't able to watch last night, but I had the exact same experience 15 years ago when Pathfinder landed.

I watched NASA's live broadcast on my HTC 1X while doing my morning (europe) exercise around my lake in my " backyard". Tears rolled, thinking about how 'humanity' and tech made this all possible to see this ' live'....

When I first saw the sheer complexity of this Mars landing, I thought this was so complex that it was bound to fail somehow. I'm glad to see I was wrong. That's an heck of an achievement that the NASA pulled off.

Absolutely. If I saw a landing sequence like this in a scifi movie, I'd be shaking my head "no way that'd ever work". And it did! The sky crane thing was unbelievable. Amazing. Congrats Nasa!

Is there a technical reason for pictures still being done in black / white?

only reason I can think of is transmission bandwidth. Besides, at NASA they already know how the surrounding of the landing zone looks like. the small pics and being in black-n-white was to ensure that the immediate surroundings are ' clear', that the rover is ' ok' and cameras working.

Is there a technical reason for pictures still being done in black / white?

They won't deploy the camera mast with the color cameras until later this week after they thoroughly check the systems. Also, the initial data link was 8kbps IIRC. It'll be a while before they get 128k or 256k relaying through Odyssey or 2mbps through MRO - 32k is the max for direct communication with no relay.

Edit: Actually I guess they could be running faster already, but there'd be little point because the color cameras aren't deployed. They could send back full resolution b&w hazcam images though, 1024x1024 (512x512 is the highest so far).

Agreed -- this is amazing -- though I'm a little biased since my cousin is on the Curiosity team (he's an engineer and helped design the rover and it's landing apparatus).

That would make for an interesting story in and of itself. As a job though I couldn't do it. The urge to take a rocket sled for ride would surely outweigh common sense in my case. Employment is hard enough to find already without that black mark on the 'ol résumé.

Quote:

Well if the Americans would come to the dark side and embrace the Metric system, these things wouldn't happen

<sigh> I have to switch hands on occasion to prevent a permanent facial malformation due to constant faceplam here in the US.

Is there a technical reason for pictures still being done in black / white?

The photos we have right now are from low-res cameras used only for landing & status monitoring. When the mast is opened up, better cameras will fire up.

On earlier rovers, the "color" images were actually composites of 3 images - each taken with a different filter over the sensor. IOW, the sensor really was just black & white, but by using filters & then putting the images together, they can create a color image. Your digital camera works similarly.

Amazing accomplishment! The scientists and engineers at NASA and JPL have every right to be proud. I have a big exam to study for but I couldn't sleep at all last night, even after knowing Curiosity landed safely.

Congrats to the team that made this possible. It truly is an amazing feat in every sense of the word. I stayed up past midnight (Central time) watching the landing and I have to say, I've never been in awe as I was then. Amazing!